Heating system



HEATING SYSTEM Filed April 15, 1955 gwwm Paul E. Seep'e Gum/wag p ying heat to the outdoor Patented Apr, 6, 1937 UNITED STATES PATENT, OFFICE} Minneapolis-Honeywell Regulator Minneapolis, Minn., a corporation of Company, Delaware Application April 15, 1935, Serial nalaz'zs 9 Claims. (Cl. 2236-91) This invention relates to heating systems of the type disclosed in the application of Daniel G. Taylor, Serial No. 512,887, filed February 2, 1931.

The system disclosed in the above referred to Taylor application comprises an outdoor controller responsive to outdoor atmospheric conditions including temperature, wind and sun for controllingthetemperature within the building. Heating means are provided in the building for supplying heat to the building and heating means are also provided in the outdoor controller for supcontroller. The two heating means are proportioned according to the heat losses from the building and from the outdoor controller. A thermostatic device is provided for responding to the temperature within the outdoor controller and when this thermostatic device calls for heat both of the heating means are energized to deliver heat to the building and to the outside controller. Due to the proportional relationship of the heating means with the heat losses of the building and the outside controller, a definite temperature relation is maintained within the building and the outside controller so that by responding to the temperature of the outside controller, the thermostatic device maintains a constant or normal temperature within the building.

Such a system gives excellent results when the system is maintained in operation for twentyfour hours a day. However, it is often desirable to shut down the heating system during the night to lower the temperature within the building to conserve on fuel-costs. But, due to the fundamental theory of operation, the system of the Taylor application cannot supply suflicient heat to the building in the morning after a night shut down to rapidly raise the temperature to normal and thereafter maintain the temperature in the building at normal.

This is caused by the fact that only suflicient heat is supplied to the building to maintain the temperature thereof constant according to variations in outside atmospheric conditions, In order to successfully operate the system of the type disclosed in the above referred to Taylor application where it is desired to have a night shut down, it is necessary that some independent means be provided for raising the temperature in the building to normal after a night shut down.

Therefore, it is an object of this invention to provide a morning pick-up control of the heating system whereby the building temperature is brought up to normal so that the temperature of the building may be maintained at normal by the outdoor controller.

Another object is to provide a meansjfor controlling the temperature in a building-duringthe day time according to variations in outside weather conditions and to provide means for night control at a lowered temperature in response to temperatures existing within the'building. Y

' Another object is to provide a night control for a building to maintain the building at lowered temperatures during the night, to provide for raising the temperature in the morning up to normal, and to provide for controlling thetemperature of the building during the day time according to outside weather conditions.

A further object is to provide automatic means for shifting the control of the building from night inside temperature control to morning pick-up control and to day-time outside control.

Further, another object is'to provide as a safety measure a high limit building control to prevent excessive temperatures from occurring in the building when the heating system'is under the control of any of the controllers.

Other objects and advantages will become ap-. parent to those skilled in the art by reference to the accompanying specification, claims and drawing in which drawing is diagrammatically shown the preferred form of my invention. a

The heating system of my invention is capable of controlling any type'of building whether it be a house used for domestic purposes or a large :building used for omces or stores. A portion of the building is diagrammatically disclosed in the drawing, the building having an outside wall to. One of the spaces to be heated is designated at ll. Located in each of the spaces to be heated II is a radiator I! which receives heating fluid such as steam from a riser l3. The supply of I heating fluid to the riser I3 is controlled by means of a valve I 4 which is connected between the riser I3 and a supply pipe l5. leading from some source of heating fluid, not shown. Heating fluid may be supplied to the pipe l5 by a usual boiler or by a central heating system. Extending from the valve i4 is a valve stem l6 which is connected by'means of a pitman IT. to a crank disc l8. Crank disc I8 is mounted on a rotatable shait l9 which is rotated by a reduction gear train interposed between the shaft 1 9 and a motor rotor The motor rotor 2! is operated upon energization of a motor field 22. One end of the motor field 22 is connected'to one end of a primary 23 of a step-down choke type transformer 24. The other end of the primary 23 of the transformer is connected by means of a wire 25 to a line wire 28 and the other end of the field 22 is connected by means of a wire 26 to another line wire 21. The line wires 21 and 28 receive their power from some source, not shown.

Secured to the shaft |9.is a slider 29 which rotates with the rod l9 and is adapted to engage either contact 30 or contact 3|. Located in the path of the movement of the slider 29 and in con-' tact therewith when the slider is,not in engagement with the contacts 30 and 3| is a conducting track 32. One end of the secondary 33 of the stepdown choke type transformer 24 is connected by means of a wire 34 to the slider 29. The other end of the secondary 33 is connected by means of wires 35 and 36 to a basement switch arm 31. The basement switch arm 31 is adapted to engage either of contacts 38, 39, and 40. Contact 38 is connected by means of a wire 4| to the contact 3| and the contact 40 is connected by means of wires 42 and 43 to the contact 30. A wire 44 connected to the junction of wires 35 and 36 is connected to the conducting track 32.

The valve I4 is shown in the open position. By

' moving the basement switch arm 31 into engagement with the off contact 40, the secondary 33 of the choke type transformer 24 is short-circuited by means of wires 35 and 36, switch arm 31, contact 40, wires 42 and 43, contact 30, slider 29 and wire 34. Upon shorting of the secondary 33 in this manner, current is allowed to flow from line wire 28 through wire 25, primary 23, field 22 and wire 26 back to the line wire 21 to start movement of the valve |4 towards its closed position. As the valve so begins to move, the slider 29 engages the track 32 thereby completing a maintaining circuit from the secondary 33 through wires 35 and 44, track. 32, slider 29 and wire 34 back to the secondary 33. By reason of this maintaining circuit, complete operation of the motor and consequent closing movement of the valve I4 is assured. Closing movement of the valve will continue until the. slider 29 moves out of engagement with the track 32-and into engagement with the contact 3| whereby the above related closing circuits for the valve are broken and the valve M will therefore remain in closed position. With the valve i4 in closed position and with the basement switch arm 31 moved to engagement ,with the on contact 38, the secondary 33 is shortcircuited through wires 35 and 36, switch arm 31,

contact 38, wire 4|, contact 3|, slider 29 and wire 34- whereby the motor will be placed in operation and the valve will be started on its movement in the opening direction. This opening movement of the valve causes the slider 29 to disengage .the contact 3| and come into engagement with the track 32 whereby a maintaining circuit is completed from the secondary 33 through-wires 35 and 44, track 32, slider 39 and wire 34 to. complete the opening movement of the valve H. The opening movement of the valve M will continue until the slider 29 disengages the track 32 and comes in contact with the contact 30 when it will be terminated and placed in condition for closing movement.

When the basement switch 31 is brought into engagement with the -automatic contact 39, the valve I4 is conditioned for opening andclosing movement by the various controls to be described hereafter.

. An outside controller responsive to outside at mospheric conditions such as temperature, wind and sun is generally designated at 45. This outside controller 45 is disclosedin deta l 1. 1 above referred to application of Daniel G. Taylor. Briefly, the outside controller consists of a block 46 enclosed within a casing 41. The block 46 is hollowed out and contains a container 48 in which is mounted by means of a post 50 a bimetallic element 49. The bimetallic element 49 is so arranged that it responds to the temperature of the bimetallic block 46. Mounted on the bimetallic member 49 are two contacts 5| and 52 which are adapted to sequentially engage contacts 53 and 54. Contacts 53 and 54 are made adjustable in order to obtain the proper operating differentials. Upon a decrease in temperature of the block, contact 54 is engaged by contact 52 and upon a further slightdecrease in temperature, contact 53 is engagedby contact 5|. The block 45 is heated by means of a heater designated at 55.

Primary 58 of a step-down transformer 59 is connectedto the line wires 21' and 28 by means'of wires 56 and 51 respectively. The step-down transformer 59 is provided with a secondary 60.

A relay coil 6| is operatively connected to switch arms 62, 63 and so that upon energization of relay coil 6|, the switcharms 62, 63 and 64 are moved to the left and upon 'deenergization thereof, they are moved to the right by means of springs or gravity or other means, not shown.

The switch arms 62, 63 and 64 are adapted to-engage contacts 65, 66, 61,-and 68. Upon energization of the relay coil 6|, the switch arms 62, 63,

and 64 are moved into engagement'with contacts 65, 66 and.68, respectively, and upon deenergization of the relay coil 6|, the switch arms are moved out of engagement with these contacts and the switch arm 63 is moved into engagement with the contact 61.

gone end of the secondary 60 of the step-down transformer 59 is connected by means of a wire 69 to the stationary contact 54. The other stationary contact 53 is connected by means of a wire 10 and a wire 1| to one end of the relay coil 6|. The other end 'of the relay coil 6| is connected by means of a wire 12 to the other end of the secondaryfill. The' post 50 which supports the bimetallic element 49 is connected by means of a wire 13 to the contact 65 and the switch arm 62 is connected by means ofa wire 14 to the junction of wires 10 and 1|.

When the temperature of block 46 of the outdoor controller 45 drops to a predetermined value, contact 52 first engages contact '54 and subsequently. contact 5| engages contact 53. When contacts 5|, 53, 52 and 54 re made, a circuit is completed from the sec ndary 60 of the step-down transformer 59- through wire 69, contacts 54, 52, 5| and 53, wire 19, wire 1|, relay coil 6| and wire 12 back to the secondary 60. This causes energization of the, relay 6| to move the switch arms 62,63 and.64 into engagement;

with contacts 65, 66;a.nd GIL-respectively. Upon closing of these relay switches by the comple-' tion of the above described circuit, a second or,

the relay coil 6| will remain energized until the temperature-of the block 46 rises to a sufficient valueto break contact between contacts 52 and 54. From the above, it is seen that upon a call for heat by the bimetallic element 49, in response to a low block temperature, the relay 6| is energized to close the relay switches 62, 63 and 64.

This invention contemplates the use of a time switch for automatic operation although the functions of the time switch may be performed manually. The time switch is diagrammatically shown to include adjustable cams 15, 16, 11 and 18 all mounted on a cam shaft 19. The shaft. 19 is driven through a reduction gear train 80 by a motor rotor 8|. The field 82 of the motor is connected by means of wires 83 and 84 to a 10 secondary 85 of a step-down transformer 86. The primary 81 of this transformer is connected by means of wires-88 and- 89 to the line wires 28 and 21, respectively. The motor 8| drives constantly the shaft 19 through the gear train 80 at such a speed that the shaft 19 and thecams 15, 16, 11, and 18 driven thereby are rotated once during every twenty-four hours in the direction shown by the arrows. Riding on the surface of earns 15, 16, 11, and 18 are contact arms 90, 9|,

20 92, and 93, respectively. When the low dwells of the cams are engaged by the contact arms, the contact arms 90, 9|, 92, and 93 are in engagement with contacts 95, 91, 99, and IOI, respectively, and when the high dwells of the cams are engaged by the contact arms, the contact arms 90, 9|, 92, and 93 are brought into engagement with the contacts 94, 96,98, and I00, respectively. a

In order to more clearly disclose the operation of this device, the cams 15., 16, 11, and 18 have been shaded in order to designate day and night surfaces thereon, the day surface being-clear and the night surface being shaded. The cams are in a' position therefore which corresponds to midnight. Upon rotation of the cams in a clockwise direction as shown by the arrows, the high dwells of cams 15 and 16 will first engage the contact arms 90 and 9| at a time corresponding to 6:00 a. m. to move the contact arms, 90 and 4 9| out of engagement with contacts 95 and 91 and into engagement with the ,contacts 94 and 96. Upon a further clockwise movement, the high dwells of the cams 11 and 18 are-engaged with the contact arms 92 and 93 at a time corresponding to substantially 8:00 a. m. to cause movement of the contact arms 92 and 93 out of engagement with the contacts 99 and IOI and into engagement with the contacts 98 and I00. The contact arms are all maintained in their upper positions until they return to the low dwells of the cams at a time which is shown to be substantially 9:00 p. m. The above specific times set forth for the operation of the contact arms are not fixed and may be varied at will by reason of the fact that the cams are made adJustable.

Located in one of the spaces to be heated II is a room high limit controller I02 which may -comprise a bimetallic member I03 for actuating a mercury switch I04. The mercury switch I04 is shown to contain four electrodes therein, the two adjacent electrodes being connected together.

' 75 wire I06 to the junction of wires 42 and 43. The

The room high limit control is so ar-. ranged that upon the existence of a tempera- .two middle electrodes, which are connected to- 66 of the relay. The contact arm 92 of the time switch is connected by means of a wire I09 to. v

the on contact 38 of the basement switch. The contact I00 of the time switch is connected by means of a wire IIO to the contact 61 of the relay switch. The contact arm 93 of the time switch is connected by means of a wire III to the o contact 40 of the basement switch.

Assume that the time of day is noon and that the contact arms 90, 9|, 92, and 93 of the time switch are held in their open positions by'the cams which position .places the system under the control of the outside controller. Also, assume that the valve I4 is in aclosed position whereby the slider 29 is in engagement with the contact 3 I. Upon a call for heat by the outside controller, the relay coil 6| is energized in the manner pointed out above to move the switch arm '63 into engagement with the contact 66 of the relay switch. By reason of such operation of the-relay, a circuit is completed from the secondary 33 through wires 35 and 36, switch arm 31 and contact 39 of the basement switch, wire I01, mercury switch I04, wire I05, switch arm 63, contact 66,wire I08, contact 98, contact arm 92, wire I09, wire 4|, con

tact 3|, slider 29 and wire 34 back to the seccndary 33 of the choke type transformer 24 to cause opening movement of the valve I4 and delivery of heat to the building. When the temperature in the outside controller rises to. a predetermined value, the relay coil 6| will be deenergized to cause switch arm 63 to engage contact 61 of the relay switch whereby a circuit is completed from the secondary 33 of the choke type transformer 24 through wire 35, wire 36, switch arm 31 and contact 39 ofthe basement switch, wire I01, mercury switch I04, wire I05,

switch arm 63, contact61, wire I I0, contact I00,

contact arm 93, wires III, 42 and 43, contact 30, slider 29 and wire 34 back to the secondary 33 to energize the valve motorto move the valve I4 to a closed position to shu fluid to the building.

If the temperature within the building becomes too high, the room high limit control will tilt the mercury switch I 04in a clockwise direction to complete a circuit from the secondary 33 of the choke type transformer through wire 35, wire 36, switch arm 31, contact 39, wire I01, mercury switch I04, wire- I06, wire 43, contact 30, slider 29 and wire 34 back to the secondary 33 to cause closing movement of the valve I4 regardless of whetherthe outside controller 45 is calling for heat. This affords a room high limit control to off the supply of heating prevent the temperature of the room or space to be heated from becoming excessive.

A wire II5 connects the line wire contact 68 of the relay switch. The 64 thereof is connected by means of 28 with the switch arm a wire II6 to one end of a primary II1 of a step-down transformer I I8 h ving'the usual secondary H9. The other end of p imary H1 is connected by means of a wire I20 to the line wire 21. I I9 of the transformer I I8 is connected by means of a wire I2I to a variable resistance I22 and the variable resistance isin turn connected by means of a wire I23 to an ammeter I24. The ammeter in turn is connected by means of a wire I25 to one end of the heating element 55 of the outside.

controller 45. The other end of the heating ele- The secondary ment 55 is connected by means of a wire I26 to the secondary II9. Therefore, when the outside controller calls for heat and energizes the relay coil 6| to cause opening of the supply of heating fluid to the building; the switch arm 64 is brought into engagement with-the contact 68 to complete a circuit through the transformer I I8 and causes a flow of current through the heater 55 by reason of its connection with the secondary II9 of transformer II8. It follows then, that every time heat is supplied to the building under the control of the outside controller, heat is likewise supplied to the outside controller to increase the temperature of the metallic block 46. Here in this case, as in the Taylor application, a proportion is set up between the heat losses from the building and from the outside controller and the amount of heat supplied to the building and to the controller. Therefore, the temperature within the outside controller 45 bears a relation with the temperature within the building so that by controlling the temperature within the outside controller the temperature within the building is similarly controlled. The variable resistances I22 and the ammeter I24 provide a means for varying and visually indicating the amount of heat supplied to the outside controller 45 whereby this ratio may be set up to afiord the proper operation of the system.

Located within the building is a day-night thermostat generally indicated at I30 having a night thermostat I3I which controls the heating system during the night and a morning pick-up thermostat I32 which controls the heating system during the morning pick-up period. The moming pick-up thermostat is adjusted to the normal day temperature within the building and the night thermostat I3I is adjusted to the night temperature which is lower than the normal. The thermostats I3I and I32 are each mounted on posts I33 and I34, respectively, and each has movable contacts I35 and I36, respectively. The contacts I35 of the night thermostat I3I are adapted to engage alternately contacts I31 and I38 and the contacts I36 of the morning pickup thermostat I32 are adapted to engage alternately contacts I39 and I40.

The posts I33 and I34 are connected together by means of wires HI and I42 and to a wire I43 which extends to the switch arm 63 of the relay switch. Contact I31 is connected by means of a wire I44 to the contact 95 and the contact I38 is connected by means of a wire I45 to the contact 91. The contact I39 is connected by means of a wire I46 to the contact 94'and the contact I40 is connected by means of a wire I41 to the contact 96. The contact arm of the time switch is connected by means of a wire I48 to the contact Since the time switch is shown in the position corresponding to midnight, the night thermostat I3I is in control. Assume that the valve I4 is in a closed position. When the temperature in the building falls below the night temperature setting, contact I35 of the night thermostat I3I engages contact I31 to complete a circuit from the secondary 33 of the choke type transformer through wire 35, wire 36, basement switch 31, contact 39, wire I01, mercury switch I04, wire I05, wire I43, wire I, post I33, thermostat I3I, contact I35, contact I31, wire I44, contact.95, contact arm 90, wire I48, contact 99, contact arm 92, wire I09, wire 4I, contact 3|, slider 29 and wire 34 back to the secondary 33 to cause operation of the valve aovasia motor. to move the valve I4. to an open position to supply heating fluid to the building. When the temperature of the building rises to the night temperature setting, then contact I35 of the night thermostat I3I engages contact I38 to complete a circuit from the secondary 33 of the choke type transformer 24 through wire 35, wire 36, switch arm 31, contact 39, wire I01, mercury switch I04,

' wire I05, wire I43, wire I, post I33, thermostat I3I, contact I35, contact I38, wire I45, contact 91, contact arm 9|, wire I49, contact IOI, contact arm 93,-wire III, wire 42, wire 43, contact 30, slider 29 and wire 34 back to the secondary 33 to cause operation of the valve motor to move the valve I4 to closed position to shut off the supply of heat to the building. In this manner, the temperature of the building is maintained at a constant temperature corresponding to the night temperature setting of the night thermostat I3I.

At 6:00 a. m., contact arms 90 and 9I are moved out of engagement with contacts and 91 by the cams 15 and 16, respectively, and into-engagement with the contacts 94 and 96. Such movement of contact arms 90 and 9| take the control of the heating-system away from the night thermostat I3I and place it under the morning pickup thermostat I32 which thermostat is adjusted for the normal day temperature. With the time switch in this latter position and with the valve l4 in the closed position and the temperature being below the normal day temperature, contact I36 of the morning pick-up thermostat I32.wil1 engage contact I39. This will complete a circuit from the secondary 33 of the choke type transformer 24 through wire 35, wire 36, switch arm 31, contact 39, wire I01, mercury switch I04, wire I05, wire I43, wire I42, post I34, thermostat I32, contact I36, contact I39, wire I46, contact 94, contact arm 90, wire I48, contact 99, contact arm 92, wire I09, wire 4I, contact 3I, slider 29 and wire 34 back to the secondary 33 to cause operation of the valve motor to move the valve I4 to open position to supply heat to the building for the morning pick-up to raise the temperature of the building to the normal day value. When the temperature of the building rises to this normal day value, contact I36 of the morning pickup thermostat I32 engages contact I40 to complete a circuit from the secondary 33 of the choke type transformer 24 through wire 35, wire 36, switch arm 31, contact 39, wire I01, mercury switch I04, wire I05, wire I43, wire I42, post I34, thermostat I32, contact I 36, contact I40, wire I41, contact 96, contact arm 9I, wire I49,'contact IOI, contact arm 93, wire III, wire '42, wire 43, contact 30, slider 29 and wire 34 back to. the secondary 33 to operate the valve motor to move the valve I4 to a closed position to shut off the supply of heat to the building.

At 8:00 a. m. in the morning, cams 11 and 18 move the contacts 92 and 93 out of engagement with contacts 99 and IOI and into engagement with contacts 98 and I00, respectively. Such movement of contact arms 92 and 93 takes the control of the heating system away from the day-night thermostat I30 entirely and places the control in the command of the outside controller and the outside controller functions to control the heating system in the manner pointed out specifically above. At 9:00 oclock at night, the earns 15, 16,11, and 18 move the contact arms 90, 9|, 92, and 93 from their upper pos ions to their lower positions as shown in the drawing to lace the night thermostat I3I in control. p

' It will be noted at this point that the room high I 2,076,518 limit control "I2 is in series with all of -the con-' From the above, it is seen that I have pro-" vided a conditioning or heating system for a building which is controlled by an outdoor controller in the day time whereby the temperatures in the building may be maintained at a predetermined value according to variations in outdoor temperature. Also, I have provided a means for taking the control away from the outside controller at night and to control the heating system by a night controller whereby a lowered temperature is maintained in the building during the night. I have also provided a means whereby the building may be brought up to normal temperature in the morning before the control is shifted to the outdoor controller. This provides for a rapid morning pick-up which could not be obtained in the Taylor applicationbecause of the fundamental features of that control.

Although I have disclosed one specificembodiment of my invention, I do not wish that my invention be limited thereto but that its scope shall be determined by the accompanying claims and the prior art. 1

I claim as my invention:

1. In a system of the class described, temperature changing means for a building, an outside controller subject to the same atmospheric conditions as the building, temperature changing means for said outside controller, means responsive to the temperature of said controller for controlling both of said temperature changing means to maintain the temperature of the building at a normal value, time means for rendering said outside controller inefiective to control said building temperature changing means whereby the, bui lding"-temperature may become other than normal, and thermostatic means for restoring the temperaturef'of the building to normal.

2. In a system of the class described, temperature changing means for a building, an outside controller subject to the same atmospheric conditions as the building, temperature changing ,means for said outside controller, means responsive to the temperature of said controller for controlling both of said temperature changing means to maintain the temperature of the building at a normal value, temperature responsive means for maintaining the building temperature at a value other than normal, temperature responsive means forrestoringthe building temperature to normal, and time means for determining which of said temperature responsive means shall be in control of said building temperature changing means. 7

3. In a system of the class described, temperature changing means for a building, temperature responsive means outside of the building for controlling said temperature changing means to maintain a normal temperature within said building, temperature responsive means inside of the building for controlling said temperature changing means to maintain a temperature within, said building other than normal, temperature responsive means inside 'of the building for controlling said temperature changing means to restore the temperature of the building to normal, and means for selecting any one of the temperature responsive means to control the tem- 75 perature cha in means.

ing means to maintain a temperature within said building other than normal, temperature responsive'means inside of the building for controlling said temperature changing means to restore the temperature of the building to normal, and time means for placing the control of the temperature changing means under' each of the temperature responsive means in sequence.

5. In a system of the class described, temperature changing means for a building, temperature responsive means outside of the building for controlling said temperature changing means to maintain a normal temperature within said building, temperature responsive means inside of the building for controlling said temperature changing means to maintain a temperature within said building other than normal, temperature responsive means inside of the building for controlling said temperature changing means to restore the temperature of the building to normal, and temperature responsive means inside of said building for rendering at least one of said temperature responsive means inoperative to control said temperature changing means.

6. In a. system of the class described, temperature changing means for a building, an'outside controller subject to the same atmospheric responsive to the temperature of said controller for controlling both of said temperature changing means to maintain the temperature of the building at a normal value, means for control-'-- ling said building temperature changing means to maintain the building at a than normal, and means for controlling said building temperature changing means to' restore the building to the normal temperature value.

temperature other 7. In a system of the class described, tem- 7 perature changing means for a building, an outside controller subject to the same atmospheric conditions as the building, temperature changing means for said outside controller, means responsive to the temperature of said controller for controlling both of said temperature changing means to maint ing at a normal value,thermostatic means for controlling said building temperature changing means to maintain the building at a temperature other than normal, thermostatic means for controlling. said building itemperature changing means to restore the building temperature to normal, and time means for shifting the control from one of said thermostatic means to the other.

8; In a system of the classdescribed, temperature changing means for a building, an outside controller subject to the same atmospheric conditions as the building, temperature changing means for said outside controller, means responsive to the temperature of said controller for controlling both of said temperature changing means to maintain the temperature of the building at a normal value, and time means and" thermostatic means responsive to the temperaain the temperature of the buildture of the building for controlling said building temperature changing ,means to maintain the building at a temperature other than normal and to restore the building temperature to ing means'to maintain the temperature of the building at a normal value means for rendering said outside controller inoperative to control said building temperature changing means.

whereby the building temperature becomes other than normal, and means ior restoring the temperature of the building to 'the normal value.-

PAUL E. SEEPE. 

